Transmission belts of flexible resilient material such as rubber are normally used in drive belt assemblies to transmit power from a driving pulley by being operably positioned in tension about and in frictional engagement with the driving surfaces of the pulleys. These belts generally contain a load-carrying section of textile cords or square-woven fabric to provide the belt with the necessary longitudinal reinforcement, stability and flexibility.
For proper operation the drive belt must be under proper tension. The tension of the belt is particularly necessary when transmission belts of a generally trapezoidal cross-section, commonly referred to as V-belts, are used since these belts are designed to wedgingly engage the V-shaped grooves of the pulleys or sheaves in order to perform their driving function.
Drive belts can be placed under tension by adjusting the center distance between the driving pulley and the driven pulley. If the pulleys are fixed so that the center distance cannot be adjusted, it is necessary to provide an "idler" or "takeup" pulley which functions to take up the slack resulting from the natural stretch of the belt in order to apply the proper belt tension.
It often happens that a belt must be replaced when the tools necessary to install and properly tension the belt are not readily available. For example, an automobile fan belt may break when the operator is far from home or a service garage. Such a situation clearly calls for an extensible drive belt which can be installed without tools.
While extensible belts are known in the art, such belts have generally required additional, often expensive, processing steps and/or materials. For example, the extensible belt set forth in U.S. Pat. Nos. 3,566,706 and 3,666,584 both to Sidney R. Fix, requires that the load-carrying cords be conditioned in a certain fashion prior to incorporating the cords into a belt body.
It is therefore an object of the present invention to provide an extensible belt.
It is another object of this invention to provide a novel method for making an extensible belt.
Other objects, aspects and advantages of the present invention will be apparent to those skilled in the art from diligent consideration of the following detailed description, the appended claims and the attached drawing.